There is 2 ways you can play it by having the manual or just write something wrong when it ask you a question and then you get to dos then you simply write "
crack.exe" and the game boots up again and now just enter some random number and it works fine.
The other way is to go use the manual on "
http://tinkerbrain.com/stunt_island/stuntisle.pdf" here you can find the airplanes and find the info about it, but they should just make so the game start from "
crack.exe" instead then it will work fine!